\\[-1.8ex] Soil Heterogeneity & $-$2.994$^{***}$ & $-$2.663$^{***}$ & $-$2.797$^{***}$ & $-$2.912$^{***}$ & $-$3.058$^{***}$ & $-$3.106$^{***}$ & $-$3.148$^{***}$ \\ 
  & (0.800) & (0.853) & (0.815) & (0.800) & (0.808) & (0.819) & (0.834) \\ 
\\[-1.8ex]
Observations & 23,437 & 23,437 & 23,437 & 23,437 & 23,437 & 23,437 & 23,437 \\ 
R$^{2}$ & 0.548 & 0.547 & 0.547 & 0.548 & 0.548 & 0.548 & 0.548 \\ 
